Cis-5-hydroxy-L-pipecolic acid (hereinafter sometimes referred to as “5OH-PA”) is a compound useful as an intermediate of pharmaceuticals and the like. It has been known that cis-5-hydroxy-L-pipecolic acid can be produced from L-pipecolic acid by biological approaches.
It has been reported that the BAB52605 protein derived from the root nodule bacterium Mesorhizobium loti strain MAFF303099 isolated from Lotus japonicus and the CAC47686 protein derived from the root nodule bacterium Sinorhizobiummeli loti strain 1021 isolated from Medicago sativa (hereinafter sometimes referred to as “SmPH”) have the ability to convert L-proline to cis-4-hydroxyproline (Patent Document 1).
It has been reported that the BAB52605 protein has the ability to convert L-pipecolic acid to cis-5-hydroxy-L-pipecolic acid though its production is relatively small (Patent Document 2).
The CAC47686 protein has also been reported to have the ability to convert L-pipecolic acid to cis-5-hydroxy-L-pipecolic acid; however, it produces cis-3-hydroxy-pipecolic acid (hereinafter sometimes referred to as “3OH-PA”) as well as cis-5-hydroxy-L-pipecolic acid in an almost equal amount from L-pipecolic acid (Patent Document 2).
Moreover, Patent Document 2 has reported that a Escherichia coli (E. coli) strain that expresses a protein encoded in a polynucleotide (cis gene), the expression of which is initiated 48 nucleotides (corresponding to 16 amino acids) upstream of the annotation of the EFV12517 protein derived from the Segniliparus rugosus strain ATCC BAA-974 (hereinafter sometimes referred to as “SruPH”), has L-pipecolic acid cis-5-hydroxylase activity and is thus able to convert L-pipecolic acid to cis-5-hydroxy-L-pipecolic acid. However, as demonstrated in Examples in this specification, this protein produces cis-3-hydroxy-pipecolic acid in a ratio of around 2%, as well as cis-5-hydroxy-L-pipecolic acid, from L-pipecolic acid.
Patent Document 3 has reported a method for producing cis-5-hydroxy-L-pipecolic acid from L-pipecolic acid. It has been reported in Patent Document 3 that the gene for SmPH is modified to reduce the production of undesirable cis-3-hydroxy-pipecolic acid and the resulting SmPH still produces cis-3-hydroxy-pipecolic acid in a ratio of around 9%.
Non-patent Document 1 has also reported that SmPH produces cis-5-hydroxy-L-pipecolic acid and cis-3-hydroxy-pipecolic acid from L-pipecolic acid. It has been reported in Non-patent Document 1 that the gene for SmPH is modified to increase the production of cis-5-hydroxy-L-pipecolic acid and the resulting SmPH still produces cis-3-hydroxy-pipecolic acid in a ratio of around 4%.